There has been proposed an electrostatic atomizer comprising an atomizing electrode, a counter electrode disposed in opposed relation to the atomizing electrode, and water supplier for supplying water onto the atomizing electrode, wherein a high-voltage is applied between the atomizing electrode and the counter electrode to atomize water held on the atomizing electrode so as to generate charged fine water droplets in a nanometer size range and in a high charge state (i.e., nanometer-size electrostatically charged or ionized misty droplets), as disclosed in the following Patent Publication 1.
Typically, this type of electrostatic atomizer disclosed in the Patent Publication 1 and others has been designed such that, after a potential of the counter electrode is set at a ground potential (zero V) as a precondition to applying an voltage in such a manner as to set a potential difference between the atomizing electrode and the counter electrode at a desired value for electrostatically atomizing water supplied onto the atomizing electrode, the voltage is applied to allow the atomizing electrode to have a potential of about minus 5 kV when it is intended to produce negatively-charged fine water droplets, or the voltage is applied to allow the atomizing electrode to have a potential of about plus 5 kV when it is intended to produce positively-charged fine water droplets.
This operation will be more specifically described with reference to a schematic diagram illustrated in FIG. 7. As shown in FIG. 7, when a voltage is applied between an atomizing electrode 2 and a counter electrode 3 to allow the atomizing electrode 2 and the counter electrode 3 to be set at +5 kV and a ground voltage (zero V), respectively, water W supplied onto the atomizing electrode 2 is electrostatically atomized to produce negatively-charged fine water droplets M and negative ions I.
In the above situation, the counter electrode is set at zero V, and a physical object C, such as an article stored in a mist-receiving space or an inner wall of a structural member defining the mist-receiving space, has an approximately zero V. Thus, most of the negative ions I produced and released into the mist-receiving space during the electrostatic atomization are likely to drift in the mist-receiving space without attaching onto the counter electrode 3, and excessively attach onto the physical object C, causing the physical object C to become electrostatically charged. Particularly, in cases where the mist-receiving space is a small volume of closed space, such as a vegetable or cooling compartment of a refrigerator, a shoes storage, a clothes washer or a dishwasher, static electrification of a physical object C due to attachment of negative ions I drifting in the small volume of closed space becomes prominent. This causes a problem that, if a user touches the physical object C by his/her hand, the static charges will be discharged through the hand to make his/her feel uncomfortable.    [Patent Publication 1] Japanese Unexamined Patent Publication No. 2006-68711